1. Field of the Invention
The invention concerns an optical conductor and an optical conductor bundle or ribbon cable.
2. Description of the Prior Art
Optical conductors are increasingly used to transmit information. They are manufactured in large quantities. It is therefore essential for the materials used in them to be of low cost and for the fabrication processes to be simple and to necessitate low cost equipment. In particular the coatings protecting the optical fiber represent an important part of the cost of fabricating an optical conductor; it would therefore be desirable to reduce the cost of the coating materials and the price of the fabrication process.
The invention is more particularly concerned with a monomode fiber optical conductor which includes an optical fiber having a diameter of approximately 125 .mu. and protection comprising a first or primary layer having an outside diameter of 185 .mu. the material of which is selected so as not to damage the glass fiber. This primary layer is itself protected by a secondary layer of a more rigid and stronger plastics material than that constituting the primary layer and the outside diameter of which is in the order of 245 .mu.. It is sometimes coated with an ink of a given color intended to identify the conductor.
The materials of the primary and secondary layers and the ink are acrylates that can be cross-linked by ultraviolet radiation. These materials are expensive and their fabrication process is costly.
A plurality of optical conductors are often assembled together to form a bundle or ribbon cable. A ribbon cable usually comprises four or twelve optical conductors. A resin that can be cross-linked using ultraviolet light is also used to assemble the conductors together and, like the materials protecting a conductor, is of high cost.
The invention aims to reduce the cost of the optical conductors and optical conductor ribbon cables and to simplify their fabrication process.